diff --git a/lib/private/AppFramework/Routing/RouteConfig.php b/lib/private/AppFramework/Routing/RouteConfig.php
index 0fde866fb7cc5..3986abd6d6eaa 100644
--- a/lib/private/AppFramework/Routing/RouteConfig.php
+++ b/lib/private/AppFramework/Routing/RouteConfig.php
@@ -130,7 +130,7 @@ protected function processRoute(array $route, string $routeNamePrefix = ''): voi
 
 		$split = explode('#', $name, 2);
 		if (count($split) !== 2) {
-			throw new \UnexpectedValueException('Invalid route name');
+			throw new \UnexpectedValueException('Invalid route name: use the format foo#bar to reference FooController::bar');
 		}
 		[$controller, $action] = $split;
 
diff --git a/lib/private/AppFramework/Routing/RouteParser.php b/lib/private/AppFramework/Routing/RouteParser.php
index d2e41f7498eb5..1b3a6c1255a42 100644
--- a/lib/private/AppFramework/Routing/RouteParser.php
+++ b/lib/private/AppFramework/Routing/RouteParser.php
@@ -93,7 +93,7 @@ private function processRoute(array $route, string $appName, string $routeNamePr
 
 		$split = explode('#', $name, 2);
 		if (count($split) !== 2) {
-			throw new \UnexpectedValueException('Invalid route name');
+			throw new \UnexpectedValueException('Invalid route name: use the format foo#bar to reference FooController::bar');
 		}
 		[$controller, $action] = $split;